Kicking off the summer box office in style, Disney and Marvel Studios' The Avengers earned $18.7 million in Thursday midnight runs, a record for a superhero title and the eighth best of all time.

In 2008, The Dark Knight grossed $18.5 million in midnight runs on its way to a weekend debut of $158.4 million -- the second-best domestic opening of all time behind Harry Potter and the Deathly Hallows Part 2, which earned $43.5 million in midnight runs last summer (the best ever) and $169.2 million for the weekend.

However, Avengers has the advantage of the upcharge from 3D; Dark Knight was released in 2D.

The Harry Potter and Twilight franchises dominate the list of best midnight earnings, thanks to a young and rabid fan base. And earlier this year, The Hunger Games grossed $19.7 million in midnight runs on its way to a weekend debut of $152.3 million, the third-best ever.

Avengers should do big business in Imax locations, where it turned in $1.31 million in midnight earnings from 273 locations.

The tentpole, which unites key Marvel superhero characters, is widely predicted to clear $150 million in its domestic debut; just how much more is up for debate. It is the first Marvel title marketed and distributed by Disney since it bought Marvel.

The Joss Whedon-directed 3D film already has earned $300 million overseas in slightly more than a week of play, topping the total lifetime grosses for Iron Man ($267 million), Thor ($268 million) and Captain America: The First Avenger ($192 million) -- whose characters also are in Avengers. It should eclipse Iron Man 2 ($311.5) by Saturday at the latest.

Avengers should finish the weekend with a whopping global haul of at least $550 million, considering it's also launching in Russia and China.

In North America, the movie is outpacing all previous Marvel films -- including the Spider-Man franchise -- in terms of advance ticket sales, as well as last year's Transformers: Dark of the Moon, according to online ticketing service Fandango.

Spider-Man 3, debuting on the same early-May weekend in 2007, opened to $151.1 million (then the biggest debut of all time domestically).

In terms of weekend records, only three other films have hit $150 million or more after Spider-Man: this year's The Hunger Games ($152.5 million), The Dark Knight ($158.4 million) and crown-holder Harry Potter and the Deathly Hallows: Part 2 ($169.2 million).

Elsewhere at the domestic box office, Fox Searchlight and Participant Media hope to counterprogram with specialty pic The Best Exotic Marigold Hotel, which opens in 27 theaters in 12 markets, including New York and Los Angeles.

Marigold Hotel -- starring Judi Dench, Bill Nighy, Tom Wilkinson, Dev Patel and Maggie Smith -- already has earned more than $70 million overseas since beginning its rollout Feb. 24, including nearly $32 million in the U.K. and nearly $19 million in Australia.